Multicircuit-testing mechanism



April 7, 1931. F. B. PHJ LBRICK 1,799,438

MULTICIRCUIT TESTING MECIIIANISM Original Filed Oct. 28, 1926 2Sheets-Sheet 1 ig 1. Frederick B. P/zi/rz'c/ifl zwa M,

P L 7, 1931- F. B. PHlLBRKJK 1,799,438

MULTICIRCUIT TESTING MECHANISM Original Filed Oct. 28, 1926ZSheets-Sheec 2 Frederick .5. Pizz'ibrz'ck 3313 Mae 8 M attoznm PatentedApr. 7, 1931 UNITED STATES PATENT ()FFICE FREDERICK B. PHILBRICK, 0FNEEDHAM, MASSACHUSETTS, ASSIGNOR TO THE GAME- WELL COMPANY, OF NEWTONUPPER FALLS, MASSACHUSETTS, A CORPORATIQIT OF MIASSACHUSETTSMULTICIRCUIT-TESTING MECHANISM Original application filed October 28,1926, Serial No. 144,792. Divided and this application filed August 8,1929. Serial No. 384,372.

This invention relates to multi-circuit testing mechanism; and isparticularly suited for use in connection with fire alarm and policesignal systems in which controlling switchboards are provided forgoverning the connections between a plurality of working circuits andrespective independent duplicate batteries for supplying operatingcurrent thereto, whereby one set of the duplicate batteries may becharged or held in reserve while the other set of such duplicatebatteries is serving as a current supply for the respective workingcircuits.

This application is a division of In prior application Serial No.144,792, filed ctober 28th,1926.

The fire alarm and police signal system switchboards built prior to thisinvention have, with few exceptions, been equipped with means forobtaining volt meter and ampere meter readings arranged'in accordancewith Patent No. 668,426, dated February 19th, 1901 or Reissue Patent No.Re.

13,858, dated January 5th, 1915. As indicat ed by these prior patents,nearly all of the switching mechanism provided upon such lire alarmswitchboards is usually of the strap switch type, such as indicated atA, B and C of said Patent No. 668,426 and the switches comprising thearms WVl and W2 of said reissued patent, while the mechanism providedfor obtaining meter readings has been either of the jack and plug typeor of the sliding block type. Such differences in the types of switchingmechanism provided on the same switchboard for more or less similarfunctions has led to confusion of the operators, especially in thoseinstances when, because of the character of the service, they are calledupon to accomplish exact adjustment of circuit conditions with a degreeof celerity and exaetitude, following the development of ab normalconditions in the signaling circuits, such as to minimize possibility ofloss or mutilated signals. Furthermore, the utilization of plugs andspring jacks has been found to result in the development ofobjectionable conditions such as breakage and short circuiting offlexible conductors in cables connet-ting the plugs with the meters,because of the repeated bending to which such cables are subjected inthe course of ordinary use; accidental interruption of circuits andmutilation of signals because of loss of resiliency of spring contacts,because of corrosion of contact surfaces of plugs and jacks, or becauseof improper presentation of the plugs to the jacks, when the operatorshave been acting in haste or under stress of excitement.

Correspondingly, the manner of use and complexity of the sliding blocktype of testing switch facilities has tended to confuse users andinvolves opportunities for the development of faulty conditions whichwill result in misleading indications of the meters.

It is an object of this invention to provide multi-circuit testingmechanism suitable for embodiment in switching mechanism of a typecorresponding to the type of the other switching mechanism of theswitchboard panel and arranged to correspondingly indicate the normalityor abnormality of each switching unit.

It is a further object of this invention to provide simple and durablemeans whereby no unit of such a mechanism can be abnormally positionedwhile any other unit is abnormally positioned.

Other objects are to provide multi-circuit testing mechanism which canbe more economically and conveniently manufactured, used and repairedthan similar mechanism heretofore devised.

Other obj ects of this invention, and the features of construction bywhich they are attained, will be pointed out hereinafter in connectionwith the description of the illustrative embodiment of the invention.

For a better understanding of this invention, reference may be had tothe accompanying drawings, in which like parts are indicated by likereference characters, and in which:

Figure 1 is a diagrammatic representa- "I tion of a signalingsystem-provided with mulswitches of Fig. 1 with the actuating mechanismcover removed; and

nected to supply the conductors of a current path ordinarily referred toas a working line and the battery d is connected to other conductorsusually communicating with what is ordinarily referred'to as a chargingline, and when said switch 9 is in its opposite extreme position thebattery (Z is connected with the working line andthe battery 0 isconnected with the charging line; and the construction and arrangementof said switch 9 is such that the movement of said switch to transposerelationship of such batteries with the conductorsof such lines will 'beaccomplished without at any time depriving the workingline of currentsupply; all for reasons well understood. by those skilled in this art. I

Associated with each circuit there is provided means for operativelyconnecting a volt meter and an ammeter with-either the working line orcharging conductors, such means being here illustratively indicated asthe switches generally designated'by the letters h and 2', respectively.Each such connecting means comprises-the switch arms 21, 22 and 23 whichare pivoted at 24, 25 and 26, respectively, have their free endsconnected by the insulating yoke 27, and respectively cooperate with-thecontacts 31 and 32, 33 and 34. and 35 and 36.

Each such connecting means hasane'chanism associated therewith fornormally rctaining same in ineffective condition; such mechanism beinghere'shown as comprising a revoluble part 4-1,including an arm 42, and alink 43, one end of which link is connected with the free end of saidarm and the other end otw'hich link is connected to the yoke 27 (seealsoFigs. 2 and Said link is so disposed between said arm and said yoke.

that they may at times act as a toggle, the central pivot of which willbe in substantial alignment with its terminalpivots, and thereby resistmovement of said yoke 27 from one of its extreme positions toward theother; and

so that rotation of said revoluble part will cause the-movement of saidyoke forthe func tional "actuation of I the associated switch arms 21,22 and 23, as hereinafter more fully explained. p 7

An enclosure is provided for the revoluble part 41 and arm 42, whichenclosure comprises the wall 44 and the cover 45 (see Figs.

- 1 and 3) and carries an abutment 46, situated therein suitable :forreceiving the key-like end 48 of the actuating device 49 (see Fig. 3)and thecover 45 has a key hole opening 50 iormed therein for receivingthe end 48 of the device 49, said opening 50 being so positionedthatwhen said key-like end 48 is positioned within the recess 47, it can bewithdrawn through said opening 50 only when the revoluble part 41 is sopositionedas to'bring'the link 43 into engagement with or closeproximity to the abutment 46. p c

The conductors 61 and 62 connect the switch arms 21 and 23, of eachswitch 2', with certain of the arms of switch g and the conductors 63and 64 correspondingly connect the arms 21 and 23 of switch it withother arms of said switch g, so that, as hereinbe'fore pointed out ingreater detail, when the switches e: and f are normally positioned, an-rthe switch 9 is positioned as shown, the terminals of battery 0 will beconnected'to said arms 21 and 23 of switch it and the terminals ofbattery (Z will be connected to like arms of the switch 2' so that afterthe switch 9 of any circuit has been moved to its extreme right'handposition, the terminals of its battery 0 will be connected to thearms 21 and23 of its associated switch 6, and the terminals of itsbattery (Z will be connected to the arms 21 and 23 of its associatedswitch 72,.

Vorking line conductors 71 and 72 communicate with the switch arms 22and 23 of each working line conductor, and charging line conductors 7'3and 74 correspondingly communicate with the switch arms 22 and 23 of thecharging test switch 2' of each circuit. The contacts 31 and 33 of eachof the switches hand i are interconnected by a conductor 75; andtheswitch arms 21 and'22 of each of the switches 71 are interconnected byresistance shunt 76, for reasons which will be hereinafter more fullyexplained.

For convenience both in operation and wiring,'it is desirable that theswitches 11 for the various circuits be arranged ina rowgand that vtheswitches h for said circuits be placed in a-parallel row; 'When soarranged,' th'e current path for ammeter readings -can be readily'sorouted that the current path through an ammeter maybe provided inwhichlength "t'er M' is connected through conductor 77, to

the contacts 34 of each of the switches 7a, in the order in which theyoccur, from left to right, and to like contacts of the switches '11, inthe order in which they occur from right to left; and the other terminalof said ammoter M is connected through the conductor 78 with thecontacts 32 of said switches in reverse order.

One terminal of the volt meter V is connected through the conductor 79with the contact 32 of the switch it of circuit A, which is, in turn,connected through the conduct-or 78 with the corresponding contact ofeach of the other switches h and 2", as just explained; and the otherterminal of said volt meter is connected through the conductor 80 withthe contact of switch 2' of circuit A, and thence to the correspondingcontact of each of the other switches 71, and i.

From the foregoing it will be apparent that, when all the switches h andi are normally positioned (to the left, as shown in Fig. 1) the ammeterM and the volt meter V will be disconnected from all of the circuitsand, inasmuch as the arms 21 and 22 of each of the switches h and i willbe resting upon their contacts 31 and 33, respectively, such arms ofeach of said switches will be interconnected through its associatedconductor 75.

It, now, the key-like end 48 of the device 49 is inserted through thekeyhole 50 of any one of the switches h or i, the operation of saiddevice will move such switch from its normal position as indicated byFig. 2) to its abnormal position, which corresponds to that in whichswitch 2' of circuit B is shown in Fig. 1.

Assuming that said switch '5 of circuit 13 is so abnormally positioned,the ammetcr M and the volt meter V will be thereby operativelyassociated with whichever of the batteries c or (Z is then connected tosaid switch The current path thus established. for said ammeter M willbe in parallel with the rcsistance shunt 76 associated with said switch1', from charging line conductor 7 3, through switch arm 22, contact 36,and conductor 77 to one terminal of said ammeter, and from the otherterminal of said ammetor through conductor 78, contact 32 and switch arm21. of said switch 2', and conductor 61 through switch to one terminalof the battery thereby connected to said switch Because of theconnection thus established, it is evident that a predeterminedproportion of the current flow between charging line conductor 73 andthe battery with which it is connected will pass through the ammeter andthereby cause suitable indication. The current path established for saidvolt meter V by abnormal positioning of said switch 71, as just referredto, will be through conductor 61 from the battery connected with saidswitch by its associated switch g, through switch arm 21 ated with saidswitch 71 through the switch 9.

\Vhile thus connected, it is evident that said volt meter will indicatethe diiference of potential between the terminals of the battery thenassociated with the operated switch 2' through its associated switch 9.

It will be noted that while the switch i associated with circuit B isthus abnormally positioned, the key-like end 48 of the device 49 will beretained by the cover 45, and, if it is now desired to obtaincorresponding readings relative to the battery associated with thecharging lines of circuit A, the device 49 must first be turned so as tobring the bit of its key-like end 48 into alignment with thecorresponding portion of the keyhole 50 formed in the cover 45associated with said switch '11, thereby restoring said switch to itsnormal position and bringing the pivotal con nection between the freeend of the arm 42 and the link 43 to a position slightly below a linebetween the axis of rotation of said arm 42 and that of the point ofattachment of said link 43 with the yoke 27. When the parts are 3 theyoke 27, and the ammeter and volt inete:

terminals will be completely disconnected from the conductors 61 and 62.

Corresponding insertion and operation of the key-like end 48 of thedevice 49 in. the keyholes of the other switches h and will similarlyassociate said volt meter and ammeter with the respective ones of theother batteries, without thereby at any time causing or permitting theestablishment of any interconnection between the working lines of an twocircuits, between the charging lines of any two circuits, or between anyworking line and a charging line.

Having described my invention, what I claim and desire to secure byLetters Patent ot the United States of America is: p

1. An electric switch having a normal and an abnormal. position incombination with actuating and retaining means therefor co1nprising arevoluble part including an arm, a link so connecting said arm with saidswitch mechanism that said arm and said link may at times form a togglethe central pivot of which will be in substantial alignment with itsterminal pivots during normal position v ing of said switch, and anenclosure for said means, comprising an abutment for arresting therotation in one direction of said revoluble part upon attainment of saidarm of a position slightly beyond the aforesaid posi- Ill) tionof'alignment, said enclosure having an aperture'through which a devicemay be in serted'for the actuation of said revoluble part and so formedthat, after being so inserted, such device can be withdrawn onlyfollowing movement thereof to a position which will carry said armbeyond such alignment in the direction of said abutment.

2. An electric switch having a normal and an abnormal position incombination with anactuating and retaining means therefor comprising arevoluble part formed to facilitate engagement thereof by an intendedactuating device and including an arm, a link so connecting said armwith said switch mech anism that said arm and said link may at timesform a toggle the central pivot of which will be in substantialalignment with its terminal pivots during normal positioning of saidswitch, an abutment for arresting the rotation in one direction of saidrevoluble part upon attainment of said armof a position slightly beyondthe aforesaid position of alignment, and means for preventingdisassociation of such a device from said revolu ble part other thanwhen the position of said arm is between the aforesaid position ofsubstantial alignment and that in which its rotation is arrested by saidabutment.

3. An electric switch having a normal and an abnormal position incombination with actuating and locking means for said switch comprisingarevoluble me'mberso formed as to be suited for engagement thereofby anintended actuating device, means for preventing disassociation of such adevice from said mechanism other than when said revoluble member is in apredetermined position and means for preventing rotation of saidrevoluble member away from the position which would permitthe'disassociation of such a device therefrom in response to any stressapplied to saidswitch for movement thereof to abnormal position. i

In witness whereof, I hereunto subscribe my name, tl1is'12th day ofJune, 1929.

FREDERICK B. PHILBRICKV

